Knee-High Devices Are Gold in Closing the Foot Ulcer Gap: A Review of Offloading Treatments to Heal Diabetic Foot Ulcers

A mouldable fibreglass backslab device as a novel approach to offload chronic plantar foot ulcers: A retrospective observational audit

BACKGROUND

Pressure offloading is a critical component of plantar foot ulcer management, including diabetes-related foot ulcers (DFU). Conventional offloading options such as total contact casting and removable knee-high walkers may be unsuitable or unsuccessful in patients with morbid obesity, intermittent lower limb oedema, high exudative wounds or poor mobility. A mouldable fibreglass backslab device (BSD) may be a practical alternative to be considered in these situations.

METHODS

Data were retrospectively collected on 28 patients (29 foot ulcers) with non-healing ulcers who received a BSD to offload their foot ulcer as an extension to standard offloading care. Baseline data included: patient demographics, type of offloading prior to BSD application, date of ulcer onset, days ulcer present prior to BSD application and ulcer size at BSD initiation. Measures of success included ulcer size reduction 12 weeks post-BSD application, time to complete ulcer healing in BSD, time to 50% reduction in ulcer size post-BSD application and total number of days ulcer present.

RESULTS

The median (IQR) ulcer area and ulcer duration at baseline for 19 patients (20 ulcers) who used the BSD was 1.65 (0.4-3.8) cm2 and 531 (101-635) days. At 12 weeks, the median (IQR) ulcer area was 0.3 (0-0.55) cm2 with a median (IQR) reduction of 97 (80-100) %. Nine (45%) ulcers achieved complete wound healing (100% reduction in wound size) at 12 weeks post-BSD application, and the remaining 11 (55%) ulcers achieved at least 50% reduction in wound size. The median (IQR) time to complete wound healing and 50% reduction in wound size was 71 (35-134) days and 24 (15-44) days, respectively. Nine patients ceased use of the BSD and reverted to conventional offloading before their wounds had healed. Of these, four patients achieved a 50% reduction in wound size at the 12-week mark with conventional offloading.

CONCLUSION

Our preliminary data suggests that a mouldable fibreglass BSD may be a practical offloading option in the management of DFUs, especially when conventional offloading methods are unsuccessful, unsuitable or unacceptable to patients. Higher level evidence is required to demonstrate suitability or efficacy of the BSD compared to current evidence-based recommended offloading methods.

Management of Diabetic Foot Ulcers with Two Forefoot Offloading Techniques: Case Series

ABSTRACT

Offloading is a key principle to healing diabetic foot ulcers. Nonremovable knee-high offloading devices are considered the criterion standard for offloading plantar forefoot ulcers. However, patients exhibit a limited tolerance for these devices, which contributes to a lack of use. In this case series describing two patients, the authors share two alternative offloading modalities for the treatment of diabetic plantar forefoot ulcers. One patient was managed using a football offloading dressing, and the other was managed with a modified felted football dressing. The football and modified felted football offloading dressings provide a cost-effective, less time-consuming application and often are a better-tolerated alternative to nonremovable knee-high offloading devices. Clinical findings support further investigation into dressing options tolerated by patients with improved adherence and optimal healing outcomes.

Extracellular matrix-inspired biomaterials for wound healing

Diabetic foot ulcers (DFU) are a debilitating and life-threatening complication of Diabetes Mellitus. Ulceration develops from a combination of associated diabetic complications, including neuropathy, circulatory dysfunction, and repetitive trauma, and they affect approximately 19-34% of patients as a result. The severity and chronic nature of diabetic foot ulcers stems from the disruption to normal wound healing, as a result of the molecular mechanisms which underly diabetic pathophysiology. The current standard-of-care is clinically insufficient to promote healing for many DFU patients, resulting in a high frequency of recurrence and limb amputations. Biomaterial dressings, and in particular those derived from the extracellular matrix (ECM), have emerged as a promising approach for the treatment of DFU. By providing a template for cell infiltration and skin regeneration, ECM-derived biomaterials offer great hope as a treatment for DFU. A range of approaches exist for the development of ECM-derived biomaterials, including the use of purified ECM components, decellularisation and processing of donor/ animal tissues, or the use of in vitro-deposited ECM. This review discusses the development and assessment of ECM-derived biomaterials for the treatment of chronic wounds, as well as the mechanisms of action through which ECM-derived biomaterials stimulate wound healing.

The Stress of Measuring Plantar Tissue Stress in People with Diabetes-Related Foot Ulcers: Biomechanical and Feasibility Findings from Two Prospective Cohort Studies

Reducing high mechanical stress is imperative to heal diabetes-related foot ulcers. We explored the association of cumulative plantar tissue stress (CPTS) and plantar foot ulcer healing, and the feasibility of measuring CPTS, in two prospective cohort studies (Australia (AU) and The Netherlands (NL)). Both studies used multiple sensors to measure factors to determine CPTS: plantar pressures, weight-bearing activities, and adherence to offloading treatments, with thermal stress response also measured to estimate shear stress in the AU-study. The primary outcome was ulcer healing at 12 weeks. Twenty-five participants were recruited: 13 in the AU-study and 12 in the NL-study. CPTS data were complete for five participants (38%) at baseline and one (8%) during follow-up in the AU-study, and one (8%) at baseline and zero (0%) during follow-up in the NL-study. Reasons for low completion at baseline were technical issues (AU-study: 31%, NL-study: 50%), non-adherent participants (15% and 8%) or combinations (15% and 33%); and at follow-up refusal of participants (62% and 25%). These underpowered findings showed that CPTS was non-significantly lower in people who healed compared with non-healed people (457 [117; 727], 679 [312; 1327] MPa·s/day). Current feasibility of CPTS seems low, given technical challenges and non-adherence, which may reflect the burden of treating diabetes-related foot ulcers.

The Why, What and Where Podcast on the Updated 2023 IWGDF Guideline on Offloading Treatments for Diabetes-Related Foot Ulcers

In this podcast the lead authors of the 2023 International Working Group on the Diabetic Foot (IWGDF) guideline on offloading treatments for diabetes-related foot ulcers briefly discuss why we need offloading treatments for people with diabetes-related foot ulcers, what the new international offloading guideline recommends, and where offloading treatment might go into the future.A podcast audio is available with this article.

Effectiveness of offloading interventions for people with diabetes-related foot ulcers: A systematic review and meta-analysis

BACKGROUND

Offloading treatment is crucial to heal diabetes-related foot ulcers (DFU). This systematic review aimed to assess the effectiveness of offloading interventions for people with DFU.

METHODS

We searched PubMed, EMBASE, Cochrane databases, and trials registries for all studies relating to offloading interventions in people with DFU to address 14 clinical question comparisons. Outcomes included ulcers healed, plantar pressure, weight-bearing activity, adherence, new lesions, falls, infections, amputations, quality of life, costs, cost-effectiveness, balance, and sustained healing. Included controlled studies were independently assessed for risk of bias and had key data extracted. Meta-analyses were performed when outcome data from studies could be pooled. Evidence statements were developed using the GRADE approach when outcome data existed.

RESULTS

From 19,923 studies screened, 194 eligible studies were identified (47 controlled, 147 non-controlled), 35 meta-analyses performed, and 128 evidence statements developed. We found non-removable offloading devices likely increase ulcers healed compared to removable offloading devices (risk ratio [RR] 1.24, 95% CI 1.09-1.41; N = 14, n = 1083), and may increase adherence, cost-effectiveness and decrease infections, but may increase new lesions. Removable knee-high offloading devices may make little difference to ulcers healed compared to removable ankle-high offloading devices (RR 1.00, 0.86-1.16; N = 6, n = 439), but may decrease plantar pressure and adherence. Any offloading device may increase ulcers healed (RR 1.39, 0.89-2.18; N = 5, n = 235) and cost-effectiveness compared to therapeutic footwear and may decrease plantar pressure and infections. Digital flexor tenotomies with offloading devices likely increase ulcers healed (RR 2.43, 1.05-5.59; N = 1, n = 16) and sustained healing compared to devices alone, and may decrease plantar pressure and infections, but may increase new transfer lesions. Achilles tendon lengthening with offloading devices likely increase ulcers healed (RR 1.10, 0.97-1.27; N = 1, n = 64) and sustained healing compared to devices alone, but likely increase new heel ulcers.

CONCLUSIONS

Non-removable offloading devices are likely superior to all other offloading interventions to heal most plantar DFU. Digital flexor tenotomies and Achilles tendon lengthening in combination with offloading devices are likely superior for some specific plantar DFU locations. Otherwise, any offloading device is probably superior to therapeutic footwear and other non-surgical offloading interventions to heal most plantar DFU. However, all these interventions have low-to-moderate certainty of evidence supporting their outcomes and more high-quality trials are needed to improve our certainty for the effectiveness of most offloading interventions.

Guidelines on offloading foot ulcers in persons with diabetes (IWGDF 2023 update)

AIMS

Offloading mechanical tissue stress is arguably the most important of multiple interventions needed to heal diabetes-related foot ulcers. This is the 2023 International Working Group on the Diabetic Foot (IWGDF) evidence-based guideline on offloading interventions to promote healing of foot ulcers in persons with diabetes. It serves as an update of the 2019 IWGDF guideline.

MATERIALS AND METHODS

We followed the GRADE approach by devising clinical questions and important outcomes in the PICO (Patient-Intervention-Control-Outcome) format, undertaking a systematic review and meta-analyses, developing summary of judgement tables and writing recommendations and rationales for each question. Each recommendation is based on the evidence found in the systematic review, expert opinion where evidence was not available, and a careful weighing of GRADE summary of judgement items including desirable and undesirable effects, certainty of evidence, patient values, resources required, cost effectiveness, equity, feasibility, and acceptability.

RESULTS

For healing a neuropathic plantar forefoot or midfoot ulcer in a person with diabetes, use a non-removable knee-high offloading device as the first-choice offloading intervention. If contraindications or patient intolerance to non-removable offloading exist, consider using a removable knee-high or ankle-high offloading device as the second-choice offloading intervention. If no offloading devices are available, consider using appropriately fitting footwear combined with felted foam as the third-choice offloading intervention. If such a non-surgical offloading treatment fails to heal a plantar forefoot ulcer, consider an Achilles tendon lengthening, metatarsal head resection, joint arthroplasty, or metatarsal osteotomy. For healing a neuropathic plantar or apex lesser digit ulcer secondary to flexibile toe deformity, use digital flexor tendon tenotomy. For healing rearfoot, non-plantar or ulcers complicated with infection or ischaemia, further recommendations have been outlined. All recommendations have been summarised in an offloading clinical pathway to help facilitate the implementation of this guideline into clinical practice.

CONCLUSION

These offloading guideline recommendations should help healthcare professionals provide the best care and outcomes for persons with diabetes-related foot ulcers and reduce the person's risk of infection, hospitalisation and amputation.

A Tunable Self-Offloading Module for Plantar Pressure Regulation in Diabetic Patients

Plantar pressure plays a crucial role in the pathogenesis of foot ulcers among patients with diabetes and peripheral polyneuropathy. Pressure relief is a key requirement for both the prevention and treatment of plantar ulcers. Conventional medical practice to enable such an action is usually realized by means of dedicated insoles and special footwear. Another technique for foot pressure offloading (not in medical practice) can be achieved by sensing/estimating the current state (pressure) and, accordingly, enabling a pressure release mechanism once a defined threshold is reached. Though these mechanisms can make plantar pressure monitoring and release possible, overall, they make shoes bulkier, power-dependent, and expensive. In this work, we present a passive and self-offloading alternative to keep plantar pressure within a defined safe limit. Our approach is based on the use of a permanent magnet, taking advantage of its non-linear field reduction with distance. The proposed solution is free from electronics and is a low-cost alternative for smart shoe development. The overall size of the device is 13 mm in diameter and 30 mm in height. The device allows more than 20-times the tunability of the threshold pressure limit, which makes it possible to pre-set the limit as low as 38 kPa and as high as 778 kPa, leading to tunability within a wide range. Being a passive, reliable, and low-cost alternative, the proposed solution could be useful in smart shoe development to prevent foot ulcer development. The proposed device provides an alternative for offloading plantar pressure that is free from the power feeding requirement. The presented study provides preliminary results for the development of a complete offloading shoe that could be useful for the prevention/care of foot ulcers among diabetic patients.

Personalized Offloading Treatments for Healing Plantar Diabetic Foot Ulcers

BACKGROUND

Non-removable knee-high devices are the gold-standard offloading treatments to heal plantar diabetic foot ulcers (DFUs). These devices are underused in practice for a variety of reasons. Recommending these devices for all patients, regardless of their circumstances and preferences influencing their ability to tolerate the devices, does not seem a fruitful approach.

PURPOSE

The aim of this article is to explore the potential implications of a more personalized approach to offloading DFUs and suggest avenues for future research and development.

METHODS

Non-removable knee-high devices effectively heal plantar DFUs by reducing plantar pressure and shear at the DFU, reducing weight-bearing activity and enforcing high adherence. We propose that future offloading devices should be developed that aim to optimize these mechanisms according to each individual's needs. We suggest three different approaches may be developed to achieve such personalized offloading treatment. First, we suggest modular devices, where different mechanical features (rocker-bottom sole, knee-high cast walls/struts, etc.) can be added or removed from the device to accommodate different patients' needs and the evolving needs of the patient throughout the treatment period. Second, advanced manufacturing techniques and novel materials could be used to personalize the design of their devices, thereby improving common hindrances to their use, such as devices being heavy, bulky, and hot. Third, sensors could be used to provide real-time feedback to patients and clinicians on plantar pressures, shear, weight-bearing activity, and adherence.

CONCLUSIONS

By the use of these approaches, we could provide patients with personalized devices to optimize plantar tissue stress, thereby improving clinical outcomes.

Differences in adherence to using removable cast walker treatment during daytime and nighttime weight-bearing activities in people with diabetes-related foot ulcers

AIMS

Patients' adherence to using knee-high offloading treatment is critical to effective healing of diabetes-related foot ulcers (DFUs). Previous studies have found that patients generally have low adherence to using removable knee-high offloading treatments, yet no study has investigated whether their adherence differs during daytime and nighttime. This study aimed to investigate the levels and factors associated with adherence to using knee-high removable cast walker (RCW) treatment during daytime and nighttime weight-bearing activities in people with DFUs.

METHODS

This was a secondary analysis of data collected from a multi-centre cross-sectional study investigating adherence to using knee-high RCWs among 57 participants with DFUs. All participants had multiple socio-demographic, physiological and psychosocial factors collected, before having their adherence to using RCWs during weight-bearing activity monitored over a 1-week period using the dual activity monitor method. Adherence data were categorised into daytime (06:00-18:00) and nighttime (18:00-06:00) periods and calculated separately. Multiple linear regression was used to identify factors associated with daytime and nighttime adherence.

RESULTS

Mean adherence to using RCW during weight-bearing activities in people with DFUs was higher during daytime compared with nighttime [39.9% (SD = 18.9) versus 20.4% (SD = 16.7), p < 0.001]. Factors independently associated with lower adherence during daytime were being male, longer diabetes duration, not having peripheral artery disease (PAD), and higher perceived RCW heaviness. Factors associated with lower adherence during nighttime were higher mean daytime steps, not having retinopathy and having dyslipidaemia.

CONCLUSIONS

Adherence to using RCWs during weight-bearing activities reduced significantly at nighttime compared with daytime among people with DFUs, and this was associated with different factors. Interventions to improve adherence, in research and clinical practice, should incorporate methods to target daytime or nighttime adherence specifically.

Orthotic approach to prevention and management of diabetic foot: A narrative review

Diabetic foot is a common complication affecting more than one-fifth of patients with diabetes. If not treated in time, it may lead to diabetic foot ulcers or Charcot arthropathy. For the management of diabetic foot, shoe modifications and orthoses can be used to reduce pressure on the affected foot or provide the foot with increased stability. In addition, the shoe modifications and orthotic devices can relieve patient discomfort during walking. Appropriate shoe modifications include changing the insole material, modifying the heel height, adding a steel shank or rocker sole, and using in-depth shoes. Alternatively, a walking brace or ankle-foot orthosis can be used to reduce the pressure on the affected foot. The purpose of this narrative review was to provide a reference guide to support clinicians in prescribing shoe modifications and foot orthoses to treat diabetic foot ulcers and Charcot arthropathy.

The Interdisciplinary Approach: Preventive and Therapeutic Strategies for Diabetic Foot Ulcers

The appropriate treatment of the common diabetic foot ulcers (DFUs) in diabetic patients demands enormous human, organizational and financial resources that are finite. Interdisciplinary teams of medical and surgical specialists, as well as allied health professionals, can help to reduce the consumption of these resources, optimize treatment, and prevent DFUs. They consist primarily of vascular surgeons, endocrinologists, and orthopedic foot and ankle surgeons and are closely supported when required by infectious diseases specialists, plastic surgeons, wound care specialist nurses, podiatrists, and orthotists. A timely interdisciplinary team review in each clinic session decreases the number of hospital visits for the oftentimes-handicapped diabetic patients significantly. The interdisciplinary team clinic setup has also been shown to reduce the risk of amputations, length of hospital staz and mortality rates.

The Outcome of Surgical Treatment for the Neuropathic Diabetic Foot Lesions-A Single-Center Study

The prevalence of diabetic foot complications is continuously increasing as diabetes has become one of the most important "epidemics" of our time. The main objective of this study was to describe the appropriate surgical intervention for the complicated neuropathic diabetic foot; the secondary goal was to find the risk factors associated with minor/major amputation and good or adverse surgical outcomes. This is an observational, retrospective study conducted between 1 January 2018 and 31 December 2019, which included 251 patients from the General Surgery Department at the Dr I. Cantacuzino Clinical Hospital in Bucharest with type II diabetes mellitus and neuropathic diabetic foot complications. The surgical conditions identified at admission were the following: osteitis (38.6%), infected foot ulcer (27.5%), gangrene (20.7%), infected Charcot foot (3.6%), non-healing wound (3.6%), necrosis (3.2%), and granulated wound (2.8%). We found that a minor surgical procedure (transmetatarsal amputation of the toe and debridement) was performed in 85.8% of cases, and only 14.2% needed major amputations. Osteitis was mainly associated with minor surgery (p = 0.001), while the gangrene and the infected Charcot foot were predictable for major amputation, with OR = 2.230, 95% CI (1.024-4.857) and OR = 5.316, 95% CI (1.354-20.877), respectively. Admission anemia and diabetic nephropathy were predictive of a major therapeutical approach, with p = 0.011, OR = 2.975, 95% CI (1.244-8.116) and p = 0.001, OR = 3.565, 95% CI (1.623-7.832), respectively. All the major amputations had a good outcome, while only several minor surgeries were interpreted as the adverse outcome (n = 24). Osteitis (45.8%) and admission anemia (79.2%) were more frequently associated with adverse outcomes, with p = 0.447 and p = 0.054, respectively. The complicated neuropathic diabetic foot requires a surgical procedure mainly associated with a good outcome.

Australian guideline on offloading treatment for foot ulcers: part of the 2021 Australian evidence-based guidelines for diabetes-related foot disease

BACKGROUND

Pressure offloading treatment is critical for healing diabetes-related foot ulcers (DFU). Yet the 2011 Australian DFU guidelines regarding offloading treatment are outdated. A national expert panel aimed to develop a new Australian guideline on offloading treatment for people with DFU by adapting international guidelines that have been assessed as suitable to adapt to the Australian context.

METHODS

National Health and Medical Research Council procedures were used to adapt suitable International Working Group on the Diabetic Foot (IWGDF) guidelines to the Australian context. We systematically screened, assessed and judged all IWGDF offloading recommendations using best practice ADAPTE and GRADE frameworks to decide which recommendations should be adopted, adapted or excluded in the Australian context. For each recommendation, we re-evaluated the wording, quality of evidence, strength of recommendation, and provided rationale, justifications and implementation considerations, including for geographically remote and Aboriginal and Torres Strait Islander peoples. This guideline, along with five accompanying Australian DFU guidelines, underwent public consultation, further revision and approval by ten national peak bodies (professional organisations).

RESULTS

Of the 13 original IWGDF offloading treatment recommendations, we adopted four and adapted nine. The main reasons for adapting the IWGDF recommendations included differences in quality of evidence ratings and clarification of the intervention(s) and control treatment(s) in the recommendations for the Australian context. For Australians with plantar DFU, we recommend a step-down offloading treatment approach based on their contraindications and tolerance. We strongly recommend non-removable knee-high offloading devices as first-line treatment, removable knee-high offloading devices as second-line, removable ankle-high offloading devices third-line, and medical grade footwear as last-line. We recommend considering using felted foam in combination with the chosen offloading device or footwear to further reduce plantar pressure. If offloading device options fail to heal a person with plantar DFU, we recommend considering various surgical offloading procedures. For people with non-plantar DFU, depending on the type and location of the DFU, we recommend using a removable offloading device, felted foam, toe spacers or orthoses, or medical grade footwear. The six new guidelines and the full protocol can be found at: https://diabetesfeetaustralia.org/new-guidelines/ .

CONCLUSIONS

We have developed a new Australian evidence-based guideline on offloading treatment for people with DFU that has been endorsed by ten key national peak bodies. Health professionals implementing these offloading recommendations in Australia should produce better DFU healing outcomes for their patients, communities, and country.

Oxygen-Releasing Composites: A Promising Approach in the Management of Diabetic Foot Ulcers

In diabetes, lower extremity amputation (LEA) is an irreversible diabetic-related complication that easily occurs in patients with diabetic foot ulcers (DFUs). Because DFUs are a clinical outcome of different causes including peripheral hypoxia and diabetic foot infection (DFI), conventional wound dressing materials are often insufficient for supporting the normal wound healing potential in the ulcers. Advanced wound dressing development has recently focused on natural or biocompatible scaffolds or incorporating bioactive molecules. This review directs attention to the potential of oxygenation of diabetic wounds and highlights current fabrication techniques for oxygen-releasing composites and their medical applications. Based on different oxygen-releasable compounds such as liquid peroxides and solid peroxides, for example, a variety of oxygen-releasing composites have been fabricated and evaluated for medical applications. This review provides the challenges and limitations of utilizing current oxygen releasable compounds and provides perspectives on advancing oxygen releasing composites for diabetic-related wounds associated with DFUs.